Timing mechanism



TIMING MECHANISM P. H. CONRADSON PIIIIIIIIII Illlll Nov. 21, 1950 Filed May 7, 1947 1950 P. H. CONRADSON 2,530,599

TIMING MECHANISM Filed May 7, 1947 4 Sheets-Sheet 2 Nov. 21, 1950 P. H. CONRADSON TIMING m-qcmmsm 4 Sheets-Sheet 5 Filed May 7, 1947 Nov. 21, 1950 P. H. CONRADSON TIMING MECHANISM 4 Sheets-Sheet 4 Filed May 7, 1947 Patented Nov. 21, 1950 TIMING MECHANISM Prentice H. Gonradson, Chicago, 111., 'assignor of one-half to Thomasl. Slattery Application May'7, 1947 Serial No. 746,421

15 Claims. 1

This invention relates to timing mechanism and more particularly to a temperature and time responsive control for terminating a cooking operation.

One of the objects of the invention is to provide a control means which is simple and inexpensive with a minimum number of parts and which is extremely accurate and reliable in operation.

Another object is to provide a control means which can easily be adjusted 'to vary the control point. In a preferred construction two adjustments are provided, one of which may be set for a normal operating range and the other of which may be readily adjusted to change the control point within the range.

Another object is to provide control means in which the control is affected by flow of material from an upper to a lower chamber. The control is preferably electrical in response to the flow of a conducting material away from contacts in the upper chamber to interrupta circuit or in response to the weight of material in the lower chamber.

Still another object is to provide control means in which the flow of material is controlled by a valve in a vent passage so that the valve is required to control only air or like gas.

A further object is to provide a control means which can be reset for a subsequent operation by turning a tubular body about a horizontal axis.

A still further object is to provide a control means in which turning of the body moves a part of the cooking device from an ejecting to a cooking position.

The above and other objects and advantages of the invention will be more readily apparent from the following description when read in connection with the accompanying drawings, in which:

Figure 1 is a horizontal section of a toaster equipped with a control means embodying the present invention;

Figure 2 is an end View;

Figure 3 is a side elevation with parts broken away and in section;

Figure 4 is an enlarged partial section on the line 4-4 of Figure 1;

Figure 5 is a partial section on the line '5-5 of Figure 4;

Figure 6 is a partial end elevation with parts shown diagrammatically.

Figure '7 is a horizontal section through a portion of the mechanism shown in Figure 4;

Figure 8 is a vertical section through an alter- 2 native type of cooking device embodying the invention;

Figure 9 is a partial section on the line 9- 9 of Figure 8;

' carrier part.

Figure 1 0 is a vertical section at right angles to Figure '8;

Figure 1-1 is an enlarged partial section showing an alternative control device construction;

Figure 12 is a side elevation with parts in 'sec-' tion of still another alternative control device; Figure 1 3 is an end elevation of the control device of Figure 1 2 with parts illustrated dialgrammatically; and

Figure 14 is an end view of the valve tube of of bread may be inserted and the toasted bread may be removed. Within the casing are vertical guide wires i I for holding the bread properly posi-tioned, and suitable heating elements indicated.

generally at 12 may be provided to heat the bread and toast it. The bread is :carried by a movable carrier part l3 which is slidable vertically on posts M in the casing and which has elongated finger members l5 extending into the slots inthe casing to support the bread to be toasted. Springs illustrated generally at l6 urge the carrier part [3 upwardly to an ejecting position in which slices of bread Will be projected from the top part of the casing. The carrier part may be pressed downwardly and held in a lowered cooking position by a latch ll engageable with the. As shown in Figure 3, the latch" is normally urged to :1 released position by a spring l8 and may be held in an engaged position by :a solenoid 19. The latch I! is controlled according to the present invention by a temperature and time responsive control means. As shown, the control means comprises an elongated tubular body 2| having a central transverse hub 22 on which the body may be rotatably mounted for turning about a horizontal axis in a supporting post 23. The body 2| is preferably formed of a non-conducting material such as plastic,

glass and the like, although it could, if desired, be formed of metal by insulating therefrom the contacts to be described later. The ends of the body are closed as by means of plugs 24 and the body is formed with a central partition 25 dividing it into two chambers which are adapted to contain a fiowable material such as a conducting liquid. The partition, as best seen in Figure 6, is formed with a relatively restricted passage 26 through which material may flow from the uppermost to the lowermost of the chambers. The partition also carries contact members 21 exposed adjacent the partition and between which a circuit may be completed by a conducting liquid or the like supported on the partition. As best seen in Figure '7, the contact members 27 are connected respectively to contact rods 28 which in turn connect to contact rings 29 lying within the support 23. The contact rings 29 are engaged by brushes 35 which are connected in circuit with the solenoid is and a suitable power source so that when a circuit is completed between the con tact members 2? the solenoid l9 will be energized.

Flow of conducting liquid or like fiowable material as indicated at 32 in Figure 4 from the upper to the lower chamber is controlled by regulating the vent of air or similar gas between the chambers. For this purpose the diaphragm is formed with an elongated transverse bore 33 and vent passages 34 communicate with the bore 33 at spaced points and extend into the chambers respectively. The vent passages are of such a length that their ends will always terminate above the liquid level in the chambers so that only air or gas will flow therethrough. To control the flow through the vent pipes, a valve mechanism is provided consisting of a tubular plug 35 fitting into the passage 33 and which is equipped with an adjustment knob 35 through which its longitudinal position in the bore can be adjusted. The plug terminates at one end in a valve seat opening adjacent one of the vent pipes 34 and has a cross bore therein communicating with the other vent pipe as shown in Figure 4. A valve rod 3'! extends axially into the bore and is adapted to seat on the valve seat to close communication between the vent pipes. The valve is normally urged to its seat by a spring 38 and terminates in a head 39 having a laterally projecting flange thereon. Preferably the head 39 is adjustably connected to the valve as by threading so that the position of the head relative to the valve tip can be regulated. The flange on the head is adapted to be engaged by a thermostatic element such as a bimetal strip 4| fixedly mounted at one end in the casing 18 with its other end free to engage the flange on the head 39 to open the valve.

At the end of a cooking operation the control device may be reset by turning the body 2| about its hub 22 to reverse the positions of the chambers. It will be understood that the body is to be adjusted to positions in which the chambers are vertically displaced relative to each other and for this purpose a spring detent 43 may be provided tending to hold the body in either of two reversed positions in which the chambers are vertically displaced relative to each other. A handle 44 may be attached to the body to facilitate turning it.

According to one feature of the invention, turning of the body not only resets the control mechanism but also moves the carriage part 53 from its ejecting to its cooking position. For this purpose an extension on the hub 22 carries a cross arm 55 having a roller 46 at its opposite ends. The carriage part i3 has an extension 41 which is adapted to be engaged by the rollers 46 to move the carriage down as the body H is 3 turned. This operation is illustrated diagrammatically in Figure 6 in which the upper dotted position of the extension 4! shows the position it will occupy when the carriage part is in its ejecting position. At this time the uppermost roller will lie vertically above the axis of the bod", as shown. As the body is turned clockwise the roller will move into engagement with the extension 41 so that further turning of the body will move the carriage part down. When the carriage part reaches its bottom position as shown in full lines, the roller 46 will have moved across the carriage to a point where it can roll freely oil of the extension so that the body can turn further without interference from the carriage part. When the carriage part reaches its lowermost position the conducting liquid in the upper chamber will bridge the contacts 21 so that the solenoid 19 will be energized to engage the latch E? with the carriage and hold it in cooking position.

With the carriage in cooking position and the conducting liquid in the upper chamber as just described the heating elements l2 may be energized through a suitable conventional control (not shown) to supply heat to bread or the like supported on the fingers l5 to toast it. At this time the valve 3'! is seated so that no air can flow through the vent tubes and the liquid will be retained in the upper chamber to maintain a circuit between the contacts 2?. As the temperature in the cooking chamber rises, the thermostat 4! will deflect until it engages the flange on the head 39. It will be noted that the position at which the thermostat engages the flange is determined both by adjustment of the head on the valve rod and by the position of the plug 35 in the bore 33. The head is preferably adjusted on the valve rod to determine a cooking range, and the position of the plug may be easily adjusted in the bore 33 to produce relatively small variations in the head position within the range.

After the thermostatic strip has engaged the flange on the head, further movement thereof in response to a further temperature increase will gradually unseat the valve 31 so that air can vent from the upper part of the lower chamber into the upper part of the upper chamber. At this time liquid can flow through the passage 25 into the lower chamber. The rate of flow of liquid is determined by the extent of valve openin and by the sizes of the passage 26 and vent passages. When the valve is initially moved it will produce a throttling effect which can be varied 5 M this time the spring 18 will disengage the latch ll allowing the springs 16 to raise the carriage to its ejecting position thereby terminating the cookin operation. To reset for a subsequent operation, it is only necessary to turn the knob -44 through one-half revolution thereby to lower the carriage and to reset the control mechanism. It will be noted that ineach operation the valve will not be opened until a predetermined temperature has been reached in the cooking g-chamber and that after opening of the valve a assua e temperature and time is accordingly provided so that highly uniform results are produced.

Figures 8 to 1 illustrate an application of the invention to an egg boiling device and further illustrate minor modifications in the control device itself. As shown, the egg cooking device comprises a receptacle 18 adapted to hold water and having a heating unit 43 therein to heat the water. Preferably the heating unit is electrical although other types of heating could be employed, if desired. The receptacle carries a central guide post which slidably supports arholder 52 which may be formed with openings to receive eggs as indicated at 53. A tubular sleeve 54 is connected to the carriage 52 and terminates in a handle by which the carriage can be moved on the guide post. Preferably the guide post is slotted, as seen in Figure 10, and a stop pin 55 carried by the sleeve extends into the slot to limit movement of the sleeve andholder. Acover plate 55 may also be provided on the sleeve to close the top of the receptacle when the sleeve or holder are in their lowered or cooking positions.

The sleeve and holder are urged upward by a spring 51 which will move the holder to a position ,to move the eggs out of the water in the receptacle. To hold the sleeve and holder down in cooking position, a pivoted latch 58 is provided adapted to engage a shoulder at the lower end of the sleeve. The latch is in the form of a bell crank lever, and its outer end is connected to a solenoid plunger 59 movable in a coil 6i. A spring 82 urges the plunger upward to release the latch, and the plunger is moved down when the coil 6! is energized to engage the latch.

The coil 5! is controlled by a control device substantially similar to that illustrated in Fig-- ures l to '7 and including an elongated tubular body 63 closed at its ends and rotatably supported for turning about a horizontal transverse axis in a support 64. The tube has a central partition 65 therein formed with a passage for fiow of material from the uppermost to the lowermost chamber and has a transverse bore through the partition carrying an adjustable valve plug 55. A valve rod 61 is adapted to seat on the plug under the influence of a spring 68 and terminates at its outer end in a notched head carrying an adjusting screw 69. A bimetal strip ll mounted in the receptacle &8 is adapted to engage the adjusting screw 69 to unseat the valve and to establish communication between vent pipes extending into the respective chambers.

In this construction the body can be turned through only 180 so that it must be turned first in one direction and then the other. To prevent excessive turning, the body carries a plate or flange i3 lying adjacent the support 54 and cut out throughout half its circumference. A pin 14 carried by the support 64 will be cleared by the cut out portion of the flange 13 but will be engaged by shoulders at the ends of the cut out portion to limit turning of the body and to insure that the body will stop with the chambers vertically displaced relative to each other.

The body carries four contact rods extending axially into the body and terminating in the chambers adjacent the partition. The contact rods are connected together in pairs by contact plates 16 to which flexible leads T! are connected. The leads are of such length that turnmunicating with the opening .83.

6; ing of the bodythrough 180 is permitted without requiring movable contacts.

Inoperation with water in the receptacle the tubular body 63 may be turned so that the conducting liquid will be in the upper chamber. At this time the coil 54 will be energized so that when the holder 52 is depressed itwill be engaged by the latch and held in cooking position. Depression of the holder may energize the heating means 49 so that the water in the re ceptacle will be heated. When the water reaches the boiling point the thermostat II will have engaged the stop screw 69 and moved the valve 61 to an opened position predetermined by the setting of the screw 69 so that air can vent from the lower to the upper chamber. The conducing liquid in the upper chamber will accordingly flow into the lower chamber to break the circuit between upper contacts 15 and .deenergize the coil .Bl. Flow .of conducting liquid from the upper to the lower chamber may occupy a predetermined time interval which is fixed by the adjustment of the valve plug 56 so that a desired cooking operation will be performed. Adjustment of the plug 66 not only determines the temperature at which the valve starts to open but also determines the maximum area of the vent passage when the valve is in its fully opened position. When the coil is deenergized the spring 62 will release the latch allowing the spring 5"! to raise the holder and move the eggs out of the water.

Figure 11 illustrates a slight modification of the control mechanism in which the position of the valve parts is reversed and the valve controls flow of liquid rather than the vent passage. As shown in this figure, the control device comprises a tubular body 18 divided at its center by a partition 19. The partition is formed with a transverse bore 8| communicating with the upper chamber through an opening 82 and with the lower chamber through an axially spaced opening 83. A valve plug 84 is slidable in the bore BI and is formed with a cross bore corn The end of the valve plug is adapted to be closed by a valve rod 85 adjustably threaded into the bore and adapted to be turned to adjust its position by a knob 86. The plug carries ahead 8! at its outer end having an abutment screw 88 therein which is adapted to be moved by a thermostat 89 to move the plug away from the valve rod and open the valve. A continuous vent pipe iii extends through the partition and opens in the chambers above the liquid level therein. Contacts 92 similar to the contacts 15 of Figures 8 to 10 may extend into the chambers and may be connected to a control device such as the coil 61 of Figures 8 to 10.

In this construction the valve directly controls the flow of conducting liquid from the upper to the lower chamber and the vent pipe is effective at all times to vent the chambers.

body 93 which is open at its ends and which may, if desired, beformed of metal. The body carries a central transverse hub 94 by which it may be rotatably mounted in a support $5 for turning about a horizontal axis. A knob or handle 96 on the body facilitates turning. The hub may carry an arm 97 having rollers 98 at its ends to cooperate with the carriage part 47 so that the carriage will be lowered to cooking position when the body is turned.

The ends of the body 93 are closed by movable closures shown as formed by flexible bellows at terminating in end discs IllI. End caps Iilil may be connected to the body and may carry springs H13 normally tending to collapse the bellows and urge the end closures inwardly of the body. Each end closure may carry a magnet iil l extending slidably through the cap I92 to approach or recede from a magnetically operated switch indicated generally at I65. As shown, the switch is formed by a non-conducting tube adapted to contain a body of conducting liquid such as mercury and having a fixed contact I55 therein dipping into the mercury. A second contact Iiil is mounted in the body for pivotal movement about a supporting spring I08 and normally dips into the pool of mercury to complete a circuit. When the contact IE}? is lifted, it will disengage the mercury to interrupt the circuit. The contacts I05 and I! may be connected in circuit with a control device such as the solenoid I9 of Figure 3.

The body 93 is divided into two chambers by a central partition I69, and the partition is formed with a central, preferably rectangular, bore therethrough. Valve means are provided to control flow through the partition and, as shown, comprise a flexible tube II I formed of a material such as rubber and fitting in the bore in the partition. Preferably the tube H is of square or rectangular section, as shown in Figure i l, since a more accurate control is provided with this type of tube. The tube is adapted to be compressed to close the passage through the partition by a rod H2 slidable transversely into the partition and urged against the tube by springs I I3 engaging a cross head I I4 carried by the rod. Opposite the rod I I2 is an adjusting rod I threaded into the partition and adapted to be turned by a knob lit. the point at which the valve will open and may also be used to control the efiective area of the iiow passage between the chambers. The rod ii 2 carries a flanged head IIl which is adapted to be engaged by the thermostat ll to open the valve when the thermostat is heated to a predetermined temperature.

The chambers may carry a body of flowable material. of any desired type, although in this construction a dry, powdered or granular material such as sand is preferred. When the valve is closed, the body may be turned to bring the chamber carrying the flowable material to the top and. at the same time to lower the carriage to cooking position. At this time the spring I63 in the bottom chamber will elevate its magnet I04 so that the contact I91 will fall to the position shown in Figure 13 to complete a. circuit so that the latch I! will engage the carriage. As the thermostat AI is heated, its upper end will move to the left to open the valve so that material can flow from the upper to the lower chamber. The time required for this operation will depend upon the size of the flow passage through the tube I I I. As material flows into the lower chamber its weight The position of the rod II5 will determine acting on the end closure IUI will expand the bellows 99 and compress the spring I03 to move the magnet I04 down. As the magnet approaches the switch I05, it exerts an increasing magnetic pull on the contact I01 and when all of the material is in the lower chamber the magnet exerts suflicient pull to raise the contact I07 and break the circuit. This releases the latch I'l so that the carriage I3 may rise to its ejecting position.

While several embodiments of the invention have been shown and described in detail herein, it will be understood that they are illustrative only and are not to be taken as a definition of the scope of the invention, reference being had for this purpose to the appended claims.

What is claimed is:

1. Timing mechanism comprising means form ing a pair of vertically displaced chambers adapted to contain a flowable material, means forming a connection between the chambers through which material can flow from the upper to the lower chamber, a valve including a pair of relatively movable members to control the fiow or" material through the connection, means to adjust the position of one of the members, a spring urging the other member toward said one of the members to close the passage, an element responsive to a condition to be controlled to move said other member away from said one of the iembers to open the passage, and a control device operated by flow of material from the upper to the lower chamber.

2. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain a conducting liquid, means forming a connection between the chambers through which liquid can flow from the upper to the lower chamber, means including a valve to control the flow of liquid through the connection, operating means for the valve, spaced contacts in the lower part of the upper chamber connected by the liquid when it is in the upper chamber and disconnected when the liquid flows into the lower chamber, and an electrical control device in circuit with the contacts.

3. Timing mechanism comprising an elongated tubular body closed at its ends, means mounting the bod for turning about a horizontal transverse axis whereby either end may be at the top, a central partition dividing the body into a pair of chambers adapted to contain a conducting liquid and having a passage therein through which liquid may flow from the upper to the lower chamber. means including a valve to con trol the flow of liquid through the passage, operating means for the valve, spaced contacts projecting into the chambers adjacent the partition so that the contacts in the upper chamber will be connected by the liquid when it is in the upper chamber disconnected when the liquid flows into the lower chamber, and an electrical control device in circuit with the contacts.

4. Timing mechanism comprising means forming a pair of vertically displaced closed chambers adapted to contain a mass of flowable material,

means forming a connection between the chambers through which material ca flow from the upper chamber to the lower chamber, means forming a vent passage connecting the chambers at points above the maximum level of material terial, means'forming a, connection between the chambers through which material can flow from the upper chamber to the lower chamber, means forming a vent passage connecting the chambers at points above the maximum level of ma terial therein, a valve controlling the vent passage, a spring normally holding the valve closed, and thermostatic means to open the valve in. response to a predetermined temperature.

6. Timing mechanism comprising means form ing. a pair of vertically displaced chambers adapted to contain a fiowable material, means forming a connection between the chambers through which material can flow from the upper to the lower chamber, means forming a'ven-t sage connecting the chambers at points above the maximum level of material therein, plug adjustable in the vent passage and formed with. a valve seat, a valve shifta'ble into engagement with the valve seat to close the vent passage, the valve having a projection thereon, and a thermostatic element movable into engagement with the projection to move the valve away from the seat.

7. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain a fiowable material, forming a connection between the chambers through which material can flow from the upper to the lower chamber, means forming a vent passage connecting the chambers at points above the maximum evel of material therein, a plug adjustable in the vent passage and formed with a valve seat, a valve shiftable into engagement with the valve seat to close the vent pussage, an adjustable projection on the valve, and a. thermostatic element mounted in a fixed position and deflectable into engagement with the projection in response to temperature to move the valve away from the seat.

8. Timing mechanism comprising an elongated tubular body closed at its ends, a central partition in the body dividing it into a pair of charmbers adapted to hold liquid, means mounting the body for turning about a horizontal axis so that it can be turned to positions in which either of the chambers is above the other, the part. being formed with a passage through which liquid flow from the upper to the lower chamber, vent pipes extending into the charmbers and terminating above the maximum liquid level therein, a valve controlling communication between the vent pipes, and means to operate the valve.

9. Timing mechanism comprising an elongated tubular body closed at its ends, a central partition in the body dividing it into a pair of chambers adapted to hold liquid, means mounting the body for turning about a horizontal axis, so that it can be turned to positions in which either of the chambers is above the other, the partition being formed with. a passage through which liquid can flow from the upper to the lower chamber, the partition being formed with a transverse passage, vent pipes connected to the passage at spaced points and extending into the chambers respectively to terminate above the maximum liquid level therein, a tubular plug in the passage formed with a valve seat through which the vent pipes may communicate, means to adjust the plug longitudinally in the passage, a valve extending longitudinally into the passage to engage the valve seat, and means to move the valve to control communication between the vent pipes.

I0. Timing mechanism comprising an elongated tubular body closed at its ends, a central partition in the body dividing it into a pair of chambers adapted to hold liquid, means mount.- ing the body for turning about a horizontal axis so that it can be turned to positions in which either of the chambers is above the other, the partition being formed with a passage through which liquid can flow from the upper to the lower chamber, the partition being formed with a transverse passage, vent pipes connected to the passage at spaced points and extending into the chambers respectively to terminate above the maximum liquid level therein, a tubular plug in the passage formed with a valve seat through which the vent pipes may communicate, means to adjust the plug longitudinally in the passage,

a valve extending longitudinally into the passage to engage the valve seat, the valve extending beyond the body and having an adjustable projection thereon, and a thermostatic element to engage the projection and move the valve away from the seat.

11. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain flowable material, means forming a connection between the chambers through which material can flow from the upper to the lower chamber, means including a valve to control the flow of material through the connection, operating means for the valve, a movable closure for the bottom of the lower chamber adapted to move in response to the weight of the flowable material thereon, a magnet carried by the movable closure to move therewith, and a magnetic switch operated by the approach and recession of the magnet.

12. Timing mechanism comprising an elongated tubular body, expansible bellows closing the ends of the body, means mounting the body for turning about a horizontal transverse axis so that either end can be up, a central partition dividing the body into a pair or chambers adapted to hold fiowable material, the partition having a passage therethrough for flow of material from the upper to the lower chamber, valve means to control the flow of material through the passage, operating means for the valve means, the bellows at the lower end of the body being formed to expand when the material flows into the lower chamber, and control means operated in response to expansion of the bellows.

13. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain a fiowable material, means forming a connection between the chambers through which material can flow from the upper to the lower chamber, a two part valve to control the flow of material through the connection including a seat part having an opening therein and an elongated tapered pin part fitting into the seat opening to provide a variable area flow passage through the opening in accordance with the relative positions of the seat and pin parts, means mounting one of the parts for adjustment toward and away from the other, and thermostatic means to move the other of the parts variably toward and away from said one part in response to temperature.

14. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain a flowable material, means forming a connection between the chambers through which material can fiow from the upper to the lower chamber, means forming a vent passage connecting the chambers, a twopart valve in the vent passage including a seat part having an opening therein and an elongated tapered pin part fitting into the opening to provide a variable area flow passage through the opening, means mounting one of the parts for adjustment toward and away from the other, and thermostatic means to move the other of the parts relative to said one of the parts in response to temperature.

15. Timing mechanism comprising means forming a pair of vertically displaced chambers adapted to contain a fiowable material, means forming a connection between the chambers through which material can flow from the upper to the lower chamber, a valve to control the flow of material through the connection including a resilient tube, a first plunger engaging the tube to collapse it, thermostatic means for moving the plunger, and a second adjustable plunger engaging the tube adjustably to collapse it.

PRENTICE H. CONRADSON.

REFERENCES CITED The following references are of record in the file of this patent:

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